1. Field of the Invention
The present invention relates to a method of writing servo data onto a magnetic recording medium such as a high density flexible magnetic disk and a high density magnetic recording medium on which the servo data is written by the method.
2. Description of the Prior Art
For a high density recording magnetic disk such as a hard disk, it is required to accurately and reliably carry out positioning (i.e., tracking) of a magnetic head with respect to the tracks of the high density recording magnetic disk. For this purpose, servo data for specifying recording tracks is previously recorded on the recording surface of the magnetic disk, and the positioning control of the magnetic head is carried out by reading out such servo data. In order to write such servo data onto the magnetic disk, a device called a "servo writer" is generally used.
In this connection, in recent years, improvements in recording film compositions and the like have led to higher densities and greater storage capacities for flexible disks, such as floppy disks. This, in the same manner as was described above with reference to hard disks, servo data is also recorded onto these flexible disks to carry out accurate and reliable positioning of the magnetic head with respect to tracks.
In this case, a servo writer is also used to write servo data onto such a flexible disk, in which in order to reduce the time required to write such servo data, the servo data is written under the condition that the flexible disk is being rotated at a high rotation speed (e.g., 2000 rpm or higher).
However, in contrast with hard disks, the flexible disks are thin and soft. As a result, when such a flexible disk is rotated at a high rotation speed, surface rippling (a phenomenon that the flexible disk is waved or fluttered) is likely to arise due to deformation of the disk. When such a surface rippling occurs, a writing error of the servo data is liable to be caused, thus leading to a lowering in production yield. In this regard, it should be noted that since in such a high density recording magnetic disk a writing operation is carried out with the writing head slightly floating above the recording surface of the disk, such surface rippling greatly affects the writing accuracy.